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Carolina hemlock (Tsuga caroliniana), an endemic species to the southern Appalachian Mountains, has vast ecological value because of their associated ecosystem services such as avian nesting sites, wildlife food, and winter shelter. The non-native, invasive hemlock woolly adelgid (Adelges tsugae) has threatened the health and longevity of both Carolina and eastern hemlocks (Tsuga canadensis) in the Appalachians since their establishment in the early 1950's. Climate change may worsen this threat as warming temperatures may promote adelgid infestations as well as alter hemlock habitat. Compared to eastern hemlock, less is known about the establishment and growth dynamics of Carolina hemlock. We used dendroecological methods to describe these patterns for five Carolina hemlock populations in North Carolina and Tennessee using 1,250 tree cores. The majority of the Carolina hemlock establishment dates within the five sites were concentrated between 1920 and 1990 and tapered off such that by 2000 no recent establishment had occurred. Maj or and minor growth release events are present in the hemlock populations across the sites. Our next step is to correlate these releases with climatic and disturbance records, to gain a better understanding of how this unique ecosystem persists. Understanding the structure, composition, and establishment patterns within and across these sites is important for figuring out if Carolina hemlock growth will be sustainable with a changing climate and an increase of the deadly hemlock woolly adelgid. [ABSTRACT FROM AUTHOR]

Disturbance events such as fire and drought play a significant role in forest growth, composition, and structure. Understanding the long term effects of ecological disturbances is increasingly important as climate change continues to exacerbate natural disasters and droughts. Our study seeks to understand the disturbance history and growth rates of a mature oak-hickory stand in Pisgah National Forest, NC. We harvested cross sectional samples from the stumps of 236 recently felled mature trees. Each sample captured the tree's growth rings from pith to bark. By counting and measuring each growth ring, we gain insight into the growth patterns, release events, and ages of each sample tree. The species within the study site were divided into two functional groups based on pore size and water potential; diffuse porous (Acer and Liriodendron) and ring porous (Quercus and Carya). We hypothesize that the diffuse porous species will be more sensitive to past disturbance events compared to ring porous species. In addition, we are interested in understanding the carbon storage potential for the site. Private landowners as well as industrial timber organizations have a growing interest in a forest's ability to sequester and store carbon. However, the effect climate change will have on carbon storage remains unclear. The objectives of this study are to 1) establish a growth and disturbance history of the stand via dendrochronology and tree ring analysis and 2) quantify the carbon storage potential for each species. We hope to better understand how past disturbances, especially drought, have impacted growth and carbon storage of species prominent throughout the southern Appalachians. [ABSTRACT FROM AUTHOR]